text: function CollisionTimeline(baseUrl, getBoundingBox) {
    this.incidentCountsBaseUrl = baseUrl + 'incidents/counts.json';
    this.getBoundingBox = getBoundingBox;
  }
  
  CollisionTimeline.prototype.renderWithCurrentBounds = function() {
    var incidentCountsUrl = this.incidentCountsBaseUrl + "?bbox=" + this.getBoundingBox();
  
    var timeline = this;
    // fetch incident count data from the API
    $.getJSON(incidentCountsUrl, function(json) {
      var incidentCounts = json.incident_counts;
  
      console.log('incident counts:', incidentCounts);
      var labels = _.pluck(incidentCounts, 'year')
      var points = _.pluck(incidentCounts, 'count')
  
      timeline.render(labels, points);
    });
  }
  
  CollisionTimeline.prototype.render = function(labels, points) {
    var context = document.getElementById('line-chart').getContext("2d");
  
    var data = {
      labels: labels,
      datasets: [{
        label: "Collisions",
        fillColor: "rgba(220,220,220,0.2)",
        strokeColor: "rgba(220,220,220,1)",
        pointColor: "rgba(220,220,220,1)",
        pointStrokeColor: "#fff",
        pointHighlightFill: "#fff",
        pointHighlightStroke: "rgba(220,220,220,1)",
        data: points
      }]
    };
    var options = {
      scaleBeginAtZero: true,
      scaleFontColor: "#888",
    };
  
    // Is it ok to just keep overriding this? Do we need to blow away the existing one first?  //
    var myLineChart = new Chart(context).Line(data, options);
  }
  
  